The present invention relates generally to machinery for the production of ornamentally patterned pile fabrics, and particularly to the formation of nonwoven pile fabrics which are produced by needling pile fibers into a supporting web with the fibers arranged thereon in a particular pattern corresponding to the ornamental arrangement desired. The invention also concerns a particular method for producing such pile fabric and a needling machine for performing the method.
Prior art methods for the production of needled, ornamentally patterned, nonwoven pile fabrics are known, for example, from U.S. Pat. No. 3,705,064, wherein at least two nonwoven fabric webs strengthened by a needling operation are used to form the finished fabric. Patterning is achieved by joining together fabric webs which are solid colored or which comprise mixed colors with one of the webs being printed on one side with pigment dyes to form an ornamental pattern. The printed side of one nonwoven fabric web is arranged to face away from the unprinted side of the other nonwoven fabric web, and the webs are subsequently subjected to a needling operation from the unprinted surface so that the fibers of the unprinted web blend with the fibers of the printed web to thereby form a nap upon the printed area. In this manner, a printed ornamental pattern is produced with a soft, patterned 3-dimensional effect.
In another prior art method known from German Pat. No. 1,960,753, a patterned nonwoven needled fabric is produced by application of a glue upon side of a solid colored needled fabric web with the desired ornamental pattern penetrating into the web. After it is dried, this web is placed with the side remote from the glued side against a second differently colored needled web having mixed or contrasting colors, with both the webs being jointly needled from the glued side. In this method, the ornamental pattern is obtained by needling fibers on the unglued side of the glued web through the web to be patterned so that a pattern is formed on the visible surface appearing thereon as a finished nap. However, in the range of the glued areas, the web which is ornamentally patterned with the glue is only partially needled with the web which is to be patterned.
In still another known method according to German Pat. No. 1,960,363, production of a patterned and needled nonwoven fabric is accomplished by utilizing two solid colored or mixed colored nonwoven fabric webs which are strengthened by needling with one of the webs being printed with a differently colored pattern and with the webs being placed one upon another and needled through from the printed web side so that the fibers colored by the printing penetrate to the outer surface of the unprinted web thereby forming a visible pattern on the nonwoven fabric. A product produced by this method has upon the originally unprinted visible side the pattern of the printed rear web, with the entire visible surface having a naplike appearance due to the needling process which is effected over the entire area. Both the unprinted fibers and those which are colored by the printing process appear on the visible side and thereby produce upon the visible surface the ornamental pattern which is printed on the back of the web.
It has also been known in the prior art to print a desired ornamental pattern directly upon the visible side of a web. This, however, involves a considerable disadvantage inasmuch as when such a nonwoven fabric is used as a floor covering, the ornamental pattern will be worn off within a relatively short time due to the fact that the pattern lacks the depth which is achieved by some of the previously mentioned prior art methods. Furthermore, because the fabric is printed directly upon the visible side it loses its nappy appearance due to the printing process.
Most known methods for the production of ornamentally-patterned nonwoven fabrics involve disadvantages by virtue of the fact that several operations are required for the production of the ornamental pattern. Printing of the pattern on one side or the other of one or more of the webs which are utilized is necessary and the webs must be subsequently needled and, as in one of the known methods, glue must be applied in the form of the ornamental pattern to be achieved. Apart from the time consuming operations which are required to form the ornamental pattern by application of printing ink or glue, such known methods involve further disadvantages since considerable amounts of glue and ink must be used.
In view of the foregoing, attempts have been made in accordance with German Pat. No. 1,977,417 to produce an ornamental pattern by utilizing needles which are arranged in the form of the pattern to be effected with two differently dyed nonwoven fabric webs being placed one upon the other and then needled through only within the range of the area where the ornamental pattern is to be achieved. In this approach, the fibers of the second web which are of a different color become visible in accordance with the arrangement of the needles upon the visible side of the web. However, a disadvantage arises in this situation inasmuch as the two webs are only needled in the range or area where the ornamental pattern is desired and no needling is effected in areas or regions which are to be free of the ornamental design. A further disadvantage resides in the fact that only solid colored ornamental patterns can be produced thereby rendering patterns having multicolored configurations unattainable.
In view of the foregoing, the present invention, which proceeds from the last-mentioned method for the production of ornamentally patterned nonwoven fabrics involving needling of fibers into a supporting web only in the area corresponding to the ornamental pattern to be achieved, is intended as an improvement over such methods whereby there may be developed an approach which permits achievement of multicolored patterns and which allows the entire surface area of a nonwoven fabric to be needled during the production process.